Interchangeable golf club grip and grip assembly

ABSTRACT

A grip assembly for a golf club is adapted to be removably attached to the upper portion of a golf club shaft. This grip assembly includes a sleeve that is adapted to fit over the upper portion of the shaft and a grip portion that is adapted to provide a gripping surface for a golfer. The assembly also includes an upper mechanism for removably securing the top end of the sleeve to the golf club shaft and a lower mechanism for removably securing the bottom end of the sleeve to the golf club shaft by applying a radially-directed compression force to the sleeve on the shaft.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application No. 61/941,186 which was filed on Feb. 18, 2014, U.S. Provisional Patent Application No. 61/970,174 which was filed on Mar. 25, 2014, U.S. Provisional Patent Application No. 62/012,699 which was filed on Jun. 16, 2014, U.S. Provisional Patent Application No. 62/021,983 which was filed on Jul. 8, 2014, and U.S. Provisional Patent Application No. 62/041,997 which was filed on Aug. 26, 2014.

FIELD OF THE INVENTION

This invention relates generally to an interchangeable golf grip and grip assembly for removable attachment to the shaft of a golf club. Preferred embodiments of this invention relate to such a golf grip and grip assembly that may be adjustably located at different rotational and axial positions along the shaft.

BACKGROUND OF THE INVENTION

The golf club has changed in the hundreds of years since the game was invented. Each of today's golf clubs consists of three main components, the club head, the shaft and the grip. Over time, each of these components has been modified to improve the “feel” of the club as it strikes a ball, and to provide for more control over the path of the struck ball. Golf clubs known as “woods” are now almost uniformly made of metal. Golf club shafts are now made of metals and/or carbon fiber materials. Early golf club grips consisted primarily of a leather strap that was wrapped in overlapping fashion around the upper part of the golf club shaft. Molded grips of various elastomeric materials were subsequently developed and adapted to be slipped over the shaft and secured thereon using an adhesive. More recent developments in grips have resulted in the incorporation of a plastic or carbon fiber sleeve between the golf club shaft and the grip. However, these sleeves are also typically attached to the shaft using an adhesive.

In an effort to provide some control over the scope of changes being made to the golf club, and to provide for uniformity in golf rules, the R&A, a group of related entities including R&A Championships Limited, Company, R&A Rules Limited, Company and R&A Group Services Limited, Company, and the United States Golf Association (USGA) have jointly issued the Rules of Golf since 1952. The USGA assumes responsibility for the administration of the Rules of Golf in the United States and Mexico, whereas the R&A assumes this responsibility in 128 countries throughout Europe, Africa, Asia-Pacific and the remainder of the Americas.

The Rules of Golf now include, in Appendices II and III, detailed and specific rules regarding golf clubs and their configuration. The grip of a golf club is defined as “material added to the shaft to enable the player to obtain a firm hold. The grip must be fixed to the shaft, must be straight and plain in form, must extend to the end of the shaft and must not be molded for any part of the hands.” For clubs other than putters, the grip must be circular in cross-section, although a grip which has subtle changes in surface texture is generally considered to conform to the rules. In addition, the longitudinal axis of the grip for clubs other than putters must coincide with the longitudinal axis of the golf club shaft. However, the rules relating to grips for putters allow for non-circular cross-sections and for locating the grip on the shaft so that its axis is offset from that of the shaft. Consequently, a golfer now has hundreds of choices of putters of various sizes and configurations. Putters can have heads of various sizes, shapes and weights, shafts of various diameters and lengths, and at least 85 different grips. However, grips for putters have not previously been provided which can be positioned on a shaft in such a way as to modify the loft and lie angles of the putter.

Because conventional golf club grips, or a sleeve component thereof, are adhesively attached to the shaft, it is not possible to change a grip without first cutting it off the shaft. Consequently, the removal of conventional golf club grips from the shaft requires their destruction. Furthermore, it is a laborious process to cut an adhesively secured grip or grip sleeve from a shaft and to remove the adhesive residue so that another grip may be attached. It would be advantageous if an interchangeable golf grip and grip assembly could be provided for removable attachment to the shaft of a golf club in compliance with the Rules of Golf.

Although it is known to provide weighting systems for a golf club by which a weight may be attached to a golf club grip to change the balance of the club, it would also be advantageous if a golf club grip could be provided that inherently modifies the balance of the club. It would be particularly advantageous if a golf club grip could be provided that can be removably located at different rotational positions on the shaft in order to modify the balance of the golf club.

In addition, various techniques have been developed to provide an anti-slip characteristic to golf club grips. Thus, for example, simulated leather wrapped grips molded out of an elastomeric material with an indented spiral surface pattern are known to provide anti-slip characteristics, as are molded grips with small patterned indentations such as lines or dots.

U.S. Pat. No. 6,663,500 describes a composite grip comprising two separate segments that are adhered together to define an elongated resilient strip that is spirally wrapped around a tapered resilient sleeve. The underlying segment is preferably wider than the overlying segment and is comprised of a polyurethane layer with a backing layer of felt. The outer surface of the polyurethane layer may be heat-embossed with a friction enhancing pattern that is intended to be engaged by a golfer's hands. The overlying segment also includes a backing layer of felt, an intermediate fabric layer and a polyurethane layer. The intermediate fabric layer comprises a mesh of nylon, cotton, polyester or the like. The polyurethane layer of the overlying segment has a thickness that is sufficient to cover and impregnate the fibers of the intermediate mesh and serves to bond together the backing layer and the mesh. In one embodiment of this grip construction, the outer surface of the polyurethane layer of the overlying segment can be buffed to partially expose the fabric fibers of the intermediate mesh layer.

U.S. Pat. No. 8,323,433 describes a composite grip comprising an extruded seamless tubular elastomeric inner layer onto which a pattern of textile cords are wound. An outer seamless tubular elastomeric layer is then assembled over the cord patterned inner layer and the assembly cured in a heated compression mold. Upon removal from the mold, some material is removed from outer surface to expose some of the cord.

Both the methods of U.S. Pat. No. 6,663,500 and of U.S. Pat. No. 8,323,433 require numerous steps including a finishing step to buff or otherwise remove a portion of the outer layer to expose an underlying mesh or cord layer. It would be advantageous if a simpler method could be provided for making a grip having anti-slip surface characteristics. It would also be advantageous if this simpler method would not require a separate surface-removing step.

Notes On Construction

The use of the terms “a”, “an”, “the” and similar terms in the context of describing the invention are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising”, “having”, “including” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. The terms “substantially”, “generally” and other words of degree are relative modifiers intended to indicate permissible variation from the characteristic so modified. The use of such terms in describing a physical or functional characteristic of the invention is not intended to limit such characteristic to the absolute value which the term modifies, but rather to provide an approximation of the value of such physical or functional characteristic. All methods described herein can be performed in any suitable order unless otherwise specified herein or clearly indicated by context.

The use of any and all examples or exemplary language (e.g., “such as” and “preferably”) herein is intended merely to better illuminate the invention and the preferred embodiments thereof, and not to place a limitation on the scope of the invention. Nothing in the specification should be construed as indicating any element as essential to the practice of the invention unless so stated with specificity.

Various terms are specifically defined herein. These terms are to be given their broadest possible construction consistent with such definitions, as follows:

The term “radially-directed”, when used to describe the direction of a force applied to or with respect to a golf club shaft, refers to a direction that is perpendicular to the axis of the shaft.

The term “detent mechanism” describes a device or combination of structures that is used to mechanically resist or arrest the rotation of a device with respect to another device to which it is attached or with which it is associated. Detent mechanisms may be used to arrest rotation in a clockwise direction and/or a counterclockwise direction, or to intentionally divide a rotation into discrete increments.

The term “threaded fastener” includes bolts having external threads that are adapted to engage the internal threads of a nut, and screws having external threads that are adapted to be threaded into another component, device or member.

SUMMARY OF THE INVENTION

The invention comprises an interchangeable golf club grip assembly that is adapted to be removably attached to the upper portion of a golf club shaft. The grip assembly includes a sleeve that is adapted to fit over the upper portion of the shaft, an upper mechanism for removably securing the top end of the sleeve to the golf club shaft and a lower mechanism for removably securing the bottom end of the sleeve to the golf club shaft by applying a radially-directed compression force to the sleeve on the shaft. The grip assembly also includes a grip portion that is adapted to provide a gripping surface for a golfer.

A preferred embodiment of the sleeve is provided with a single slit that extends along its entire length and tapers so as to be wider at its bottom end (towards the club head) than at its top end, to accommodate multiple shaft diameters and shafts having varying diameters. Other embodiments of the sleeve include slits that do not extend along its entire length and slits that include cut-outs of various shapes. In one embodiment of the invention, an expansion member is provided to fit within the upper part of the shaft, and a cap is provided to fit within the upper portion of the sleeve above the expansion member. The cap has a generally cylindrical stem portion which extends downwardly into the top end of the sleeve and is secured thereto with an adhesive. In this embodiment of the invention, the expansion member is adapted to fit within the shaft just below the cap, and is hollow to receive a threaded fastener such as a bolt. The preferred embodiment of this expansion member includes an integral nut at its bottom and is adapted to expand outwardly against the inner surface of the shaft when the bolt is advanced into the nut. This causes the outwardly expanding expansion member to exert a radially directed force on the shaft inside the sleeve, which in turn, applies a radially directed force against the sleeve and the grip portion of the assembly to hold the grip assembly in place on the shaft. In another embodiment of the invention, the expansion member includes an integral cap portion and a lower portion that is provided with a plurality of expansion slots. A threaded fastener such as a screw is provided for this embodiment. This threaded fastener is adapted to expand the lower portion of the expansion member when it is advanced therein, causing the expansion member to exert a radially directed force on the shaft inside the sleeve, which in turn, applies a radially directed force against the sleeve and the grip portion of the assembly to hold the grip assembly in place on the shaft.

In other embodiments of the invention, a threaded nut is secured within the upper portion of the shaft and the sleeve includes an integral cap member that is adapted to form a detent mechanism with the threaded nut. The cap member has a hole to receive a threaded fastener which engages the threaded nut to securely attach the sleeve to the shaft. The cap member or the threaded fastener in these embodiments of the invention may be provided of different materials and of different weights in order to allow for modifying the balance of the golf club. The grip portion employed in these embodiments may have an integral overcap or a separate overcap to cover the top of the threaded fastener. In some embodiments of the invention, a separate overcap for the grip portion may be provided that is made of multiple materials, each having a different density in order to modify the balance of the golf club grip assembly. Such an overcap may have an upper surface that is relatively flat (i.e., planar) or it may be rounded to blend with the contours of the upper part of the grip portion. In other embodiments of the invention, the grip portion may be open at the top. In other embodiments of the invention, the grip portion itself may be made of multiple materials, each having a different density, with such materials occupying different radial portions of the grip assembly around the shaft. In another embodiment of the invention, there is no sleeve, and the grip portion is sufficiently rigid to support an integral portion of a detent mechanism that is adapted to engage a cooperative portion of a detent mechanism on the golf club shaft.

The invention also includes a lower mechanism for securing the grip to the shaft of the golf club by the application of a radially directed or clamping force to the shaft at a lower location. In one embodiment of the invention, the bottom end of the sleeve is externally threaded and adapted to mate with a separate nut that when tightened will cause the bottom end of the sleeve to be radially compressed onto the outer surface of the club shaft. In another embodiment of the invention, the bottom end of the sleeve is secured to the shaft by a separate clamp. The clamp may comprise a metal of plastic fitting that may be secured with a threaded fastener, or it may comprise an elastomeric band or O-ring. Fins or flares may be provided on the outer surface of at least a portion of the sleeve to assist in holding the grip securely thereon. In another embodiment of the invention, there is no sleeve, and the grip portion is sufficiently rigid to support an integral lower clamp assembly. In some embodiments of the invention, the grip portion is provided with anti-slip surface characteristics.

Preferred embodiments of the invention also include an interchangeable golf club grip assembly that may be installed on the golf club shaft in such a way that the grip axis is not coincident with the central axis of the shaft, in order to modify the loft and/or lie angles of the golf club. By providing the grip portion of the grip assembly with a bore that is angled with respect to the grip axis, the grip assembly can be placed on the shaft at an angle that will modify either or both of the built-in loft angle and the built-in lie angle of the club.

In order to facilitate an understanding of the invention, the preferred embodiments of the invention are illustrated in the drawings, and a detailed description thereof follows. It is not intended, however, that the invention be limited to the particular embodiments described and illustrated herein. Various modifications and alternative embodiments such as would ordinarily occur to one skilled in the art to which the invention relates are also contemplated and included within the scope of the invention described and claimed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial sectional view of a first embodiment of the grip assembly.

FIG. 2 is a front view of the lower portion of the grip assembly of FIG. 1.

FIG. 3A is a front view of the lower portion of an embodiment of the sleeve of the grip assembly that is provided with a plurality of fins spaced around the lower portion of the sleeve, along with an embodiment of a clamp assembly that includes a threaded fastener.

FIG. 3B is a top view of the clamp shown in FIG. 3A.

FIG. 4A is a partial schematic view of a grip portion having an integral clamp assembly and a threaded fastener.

FIG. 4B is an end view of the clamp assembly shown in FIG. 4A.

FIG. 5A is a perspective view of an elastomeric clamp member.

FIG. 5B is a top view of the elastomeric clamp member shown in FIG. 5A.

FIG. 6A is a perspective view of the cap of the assembly of FIG. 1.

FIG. 6B is a top view of the cap of FIG. 6A.

FIG. 6C is a sectional view of the cap of FIGS. 6A and 6B.

FIG. 7A is a perspective view of an alternative embodiment of the cap.

FIG. 7B is a top view of the cap of FIG. 7A.

FIG. 7C is a sectional view of the cap of FIGS. 7A and 7B.

FIG. 8 is a sectional view of a generally cylindrical spacer that may be employed in the assembly of FIG. 1.

FIG. 9A is a front view of the expansion member of the assembly of FIG. 1.

FIG. 9B is a sectional view of the expansion member of FIG. 9A.

FIG. 9C is a bottom view of the expansion member of FIGS. 9A and 9B, showing its integral nut.

FIG. 10A is a top view of the threaded fastener of the assembly of FIG. 1.

FIG. 10B is a partial sectional view of the threaded fastener shown in FIG. 10A.

FIG. 11 is a front view of a first embodiment of a tool for use with the threaded fastener of FIGS. 10A and 10B.

FIG. 12 is a side view of a second embodiment of a tool for use with the threaded fastener of FIGS. 10A and 10B.

FIG. 13 is an end view of the wrench portion of the tool shown in FIG. 11 or the tool shown in FIG. 12.

FIG. 14 is a sectional view of a second embodiment of the expansion member and its mating threaded fastener.

FIG. 15 is a sectional view of a third embodiment of the expansion member, which is formed integrally with the sleeve.

FIG. 16 is a schematic view of a first alternative embodiment of the threaded fastener illustrated in FIGS. 10A and 10B.

FIG. 17 is a schematic view of a first alternative embodiment of the threaded fastener illustrated in FIG. 14.

FIG. 18A is a bottom view of a first embodiment of a cap member that comprises a portion of a detent mechanism and is adapted to be attached to the sleeve. This embodiment of a cap member can be employed with the embodiment of the attachment mechanism shown in FIG. 18B, or with the embodiment of the attachment mechanism shown in FIGS. 19 and 20.

FIG. 18B is a perspective view, partially in section, of a first embodiment of an attachment mechanism for the upper part of the shaft comprising a threaded nut with a portion of a detent mechanism. FIG. 18B also includes the cap member of FIG. 18A, which comprises another portion of the detent mechanism.

FIG. 18C is a schematic view of the impending mating of detent features of the cap member and threaded nut illustrated in FIG. 18B.

FIG. 19 is a perspective view of a threaded nut that comprise a portion of a second embodiment of an attachment mechanism for the upper part of the shaft.

FIG. 20 is a perspective view of an upper part of a shaft that is adapted to cooperate with the nut of FIG. 19 to form a portion of a detent mechanism.

FIG. 21A is a bottom view of a second embodiment of a cap member comprising a portion of a detent mechanism that can be employed with a threaded nut similar to those illustrated in FIGS. 18B and 19 to comprise a detent mechanism that can be employed in the invention.

FIG. 21B is a side view of the embodiment of the cap member shown in FIG. 21A.

FIG. 22 is a side view of a portion of a sleeve to which the cap member of FIGS. 21A and 21B may be attached.

FIG. 23A is a perspective view of a third embodiment of a cap member which comprises a portion of a detent mechanism and is adapted to be attached to the sleeve. This cap member is adapted for engagement with the threaded nut shown in FIG. 24 or the threaded nut shown in FIG. 25 to comprise a detent mechanism that can be employed in the invention.

FIG. 23B is a bottom view of the embodiment of the cap member shown in FIG. 23A.

FIG. 24 is a perspective view, partially in section, of a portion of an attachment mechanism for the upper part of the shaft comprising a threaded nut that includes a portion of a detent mechanism that is adapted to cooperate with the cap member of FIGS. 23A and 23B.

FIG. 25 is a perspective view, partially in section, of another embodiment of an attachment mechanism for the upper part of the shaft comprising a threaded nut with a portion of a detent mechanism that is adapted to cooperate with the cap member of FIGS. 23A and 23B, and an extension member.

FIG. 26 is a perspective view, partially in section, of yet another embodiment of an attachment mechanism for the upper part of the shaft comprising a threaded nut with a portion of a detent mechanism, and an associated cap member with a cooperating portion of a detent mechanism.

FIG. 27 is a bottom view of the cap member which comprises a portion of a detent mechanism that is adapted to be attached to a sleeve for engagement with the threaded nut shown in FIG. 28 to form another embodiment of an attachment mechanism.

FIG. 28 is a perspective view, partially in section, of a portion of an attachment mechanism for the upper part of the shaft comprising a threaded nut with a portion of a detent mechanism that is adapted to cooperate with the cap member shown in FIG. 27.

FIG. 29 is a partially exploded view of a portion of an attachment mechanism for the upper part of the shaft comprising a threaded nut with a portion of a detent mechanism that is adapted to cooperate with a grip portion having an integral sleeve and detent mechanism.

FIG. 30 is a partial sectional view of another embodiment of the grip assembly.

FIG. 31A is a perspective view of the reinforcing cap that is shown in FIG. 30.

FIG. 31B is a top view of the reinforcing cap of FIG. 31A.

FIG. 31C is a sectional view of the reinforcing cap of FIGS. 31A and 31B, taken through the line 31C-31C of FIG. 31B.

FIG. 32A is a top view of a first embodiment of a separate overcap for use in connection with a grip portion of the grip assembly.

FIG. 32B is a side view of the overcap shown in FIG. 32A.

FIG. 32C is a top view of a second embodiment of a separate overcap for use in connection with a grip portion of the grip assembly.

FIG. 32D is a sectional view of the overcap shown in FIG. 32C, taken through line 32D-32D of FIG. 32C.

FIG. 33 is a sectional view of another embodiment of a sleeve for use in connection with the grip assembly that includes an internal thread feature.

FIG. 34 illustrates various sleeve portions showing alternative embodiments of a slit at the bottom thereof.

FIG. 35A is a front sectional view of a first embodiment of a grip portion that is adapted to inherently modify the balance of the golf club to which it is attached.

FIG. 35B is a top view of the embodiment of the grip portion shown in FIG. 35A.

FIG. 36A is a front sectional view of a second embodiment of a grip portion that is adapted to inherently modify the balance of the golf club to which it is attached.

FIG. 36B is a top view of the embodiment of the grip portion shown in FIG. 36A.

FIG. 37 is a front view of a mesh panel that may be employed in embodiments of the invention in which the grip portion is provided with anti-slip surface characteristics.

FIG. 38 is a perspective view, partially in section, of a mold for forming an embodiment of the invention including a folded mesh fabric layer that is adapted to provide anti-slip surface characteristics to the grip portion.

FIG. 39 is an exploded view of an alternative embodiment of a portion of a grip portion that is adapted to include anti-slip surface characteristics which comprises an underlying sleeve, a pair of spacers and a mesh fabric overlay that may also be employed in the mold of FIG. 38.

FIG. 40 is a sectional view of an alternative embodiment of a folded fabric layer that is placed directly on the mandrel prior to inserting it in the mold of FIG. 38.

FIG. 41 illustrates various alternative fabrics that may be used in connection with the invention for providing anti-slip surface characteristics to the grip portion.

FIG. 42 is a schematic view of a of a golf club grip assembly that is attached to a golf club shaft in such a way that the grip axis is not coincident with the central axis of the shaft.

FIG. 43A is a top view of the reinforcing cap that is shown in FIG. 42.

FIG. 43B is a front view of the reinforcing cap of FIG. 43A.

FIG. 44 is a side view of a golf club grip assembly that is attached to a golf club shaft in such a way that the grip axis is not coincident with the central axis of the shaft.

FIG. 45 illustrates the grip assembly and shaft of FIG. 44 in eight different angular orientations showing the effect that these orientations have on the lie angle and/or the loft angle of the club head that is attached to the shaft.

FIG. 46A illustrates the effect of a first grip assembly orientation on the loft angle of the club head that is attached to the shaft.

FIG. 46B illustrates the effect of a second grip assembly orientation on the loft angle of the club head that is attached to the shaft.

FIG. 46C illustrates the effect of a third grip assembly orientation on the lie angle of the club head that is attached to the shaft.

FIG. 46D illustrates the effect of a fourth grip assembly orientation on the lie angle of the club head that is attached to the shaft.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in FIGS. 1 and 2, grip assembly 20 is adapted to fit over hollow golf club shaft 22 having an inner surface 24. The grip assembly includes cap 26 (also shown in FIGS. 6A, 6B and 6C), and generally cylindrical sleeve 28 that has a longitudinal axis 29 which, in the embodiment shown in FIGS. 1 and 2, is coincident with the longitudinal axis of shaft 22. Sleeve 28 is provided with a single slit 30 (not shown in FIG. 1) that extends along its entire length and tapers so as to be wider at its bottom end (towards the club head) than at its top end. This slit allows grip assembly 20 to be installed on golf club shafts of various diameters. Sleeve 28 may be made of plastic, preferably acrylonitrile butadiene styrene (“ABS”), or of metal or any other suitable material, and it may be provided in various lengths to allow the grip assembly to be located at any of various axial locations along the shaft. Grip assembly 20 also includes generally hollow grip portion 32 that is adapted to fit over the sleeve. Grip portion 32 is preferably made from an elastomeric material and provided with a surface texture that can easily be gripped by the hands of a golfer. Grip portion 32 can be provided in any suitable configuration and in any convenient length. Preferably, sleeve 28 is provided with a plurality of fins 34 that are spaced around the lower portion of the sleeve. These fins are adapted to engage the inside surface of grip portion 32 and to prevent the grip portion of the assembly from rotating with respect to sleeve 28. In other embodiments of the invention, fins, ribs or other anti-rotation features can be provided in any of various longitudinal and radial locations on the sleeve.

FIGS. 1 and 2 illustrate a mechanism by which a radially directed or clamping force can be applied to the lower portion of the grip assembly to hold it securely on golf club shaft 22. As shown therein, sleeve 28 is provided with external threads 66 on its lower portion, which threads are adapted to mate with the internal threads on clamp nut 68. Sleeve 28 is also provided with lower ledge portion 70 that serves to retain clamp nut 68 on the sleeve when it is not tightened onto threaded portion 66. When clamp nut 68 is threaded onto threads 66 on the lower portion of sleeve 28, a radially directed clamping force is applied to the sleeve on the shaft.

FIGS. 3A and 3B illustrate yet another embodiment of a lower sleeve clamping mechanism. As shown therein, sleeve 128 is provided with a single slit 130 that extends along its entire length and tapers so as to be wider at its bottom end (towards the club head) than at its top end. This slit allows the grip assembly to be installed on golf club shafts of various diameters. Preferably, sleeve 128 is provided with a plurality of fins 134 that are spaced around the lower portion of the sleeve and are adapted to engage the inside surface of the grip portion to prevent it from rotating with respect to the sleeve. This embodiment of the invention also includes clamp 167 and clamp fastener 168. Clamp 167 is preferably of rigid plastic or metal and includes gap 169. Clamp 167 is adapted to encircle a bottom portion of the sleeve above lower ledge portion 170 Clamp fastener 168 is provided to engage a threaded hole in the clamp so that when the clamp is positioned on the bottom portion of sleeve 128, tightening of clamp fastener 168 will close gap 169 to apply a radially directed clamping force to the sleeve on the golf club shaft. Clamp 167 and fastener 168 are retained on the sleeve by lower ledge portion 170 when the clamp is not tightened against the sleeve.

FIGS. 4A and 4B illustrate an alternative embodiment of the invention having a grip portion that includes an integral sleeve, and also includes an integral mechanism by which a radially directed or clamping force can be applied to the lower portion of the grip assembly to hold it securely on the golf club shaft. As shown therein, grip portion 220 includes clamp 267 and clamp fastener 268. Clamp 267 is integrally formed in grip portion 220 and is adapted to encircle shaft 222 at the bottom of the grip portion. Clamp 267 is of a type that is adapted to maintain a clamping force on the shaft, and to release this clamping force by threading clamp fastener 268 in a threaded hole provided in the clamp. Threading clamp fastener 268 into the hole provided will open a gap at intersection 269 of the ends of the clamp so that the grip portion may be properly positioned on the shaft. Threading clamp fastener in the opposite direction will close the gap as shown in FIGS. 4A and 4B to create a radially directed or clamping force on the shaft.

FIGS. 5A and 5B illustrate an alternative clamp members comprising elastomeric band 195. In the alternative, a rigid plastic ring with an expansion slit, or an O-ring could be used as a clamp member.

As shown in FIGS. 6A, 6B and 6C, cap 26 is particularly adapted for use, in grip assembly 20 (see FIG. 1), in connection with expansion member 46 (also shown in FIGS. 9A, 9B and 9C). Referring now to FIGS. 6A, 6B and 6C, cap 26 has an upper lip 36 that is adapted to fit over the top of the sleeve, and a downwardly depending sidewall 38 that is adapted to fit within the upper part of the sleeve. Preferably, the upper lip and the downwardly depending sidewall are adhesively attached to the inside surface of sleeve 28 above the top of shaft 22, as best shown in

FIG. 1. Cap 26 also has an intermediate portion 40 that includes hole 42 through which a threaded fastener such as bolt 44 (also shown in FIGS. 10A and 10B) may be placed, so that the head 45 of the bolt will rest on intermediate portion 40 of cap 26. Furthermore, the portion of sidewall 38 that is located below intermediate portion 40 helps to stabilize and align expansion member 46 within shaft 22 in the embodiment of the invention shown in FIG. 1.

FIGS. 7A, 7B and 7C illustrate an alternative embodiment of the cap that can also be used with expansion member 46. As shown therein, cap 126 has a top portion 135 with an upper lip 136 that is adapted to fit over the top of the sleeve, and a downwardly depending sidewall 138 that is adapted to fit within the upper part of the sleeve. Preferably, the upper lip and the downwardly depending sidewall are adhesively attached to the inside surface of the sleeve above the top of the golf club shaft. Top portion 135 of cap 126 includes hole 142 through which a threaded fastener such as bolt 44 may be placed. Furthermore, sidewall 138 helps to stabilize and align an expansion member (such as expansion member 46) within shaft 22.

As shown in FIG. 8, generally cylindrical spacer 139 may be provided to fit atop upper lip 36 of cap 26 or top portion 135 of cap 126 to allow for a longer grip portion to be attached to sleeve 34 of the grip assembly. Multiple caps 26, caps 126 or spacers 139, each of which has a different weight, may be provided to allow a user to modify the balance of the golf club assembly by interchanging the various caps or spacers.

As best shown in FIGS. 9A, 9B and 9C, expansion member 46 includes upper portion 48 that is preferably adapted to fit within the sidewalls of a cap, and lower portion 50 that includes a plurality of expansion ribs 52. Lower portion 50 of expansion member 46 is sized and configured so that it can fit within the top end of golf club shaft 22, as shown in FIG. 1. Preferably, the lower portion of the expansion member extends downwardly for at least ½ inch from the top of the shaft in its unexpanded state. Expansion member 46 is provided with central hole 54 that is adapted to receive a threaded fastener such as bolt 44, and an integral nut 56 is provided at the lower end of the expansion member. Nut 56 is threaded so as to mate with threaded bolt 44, and expansion member 46 is made of compressible material, so that advancing bolt 44 into nut 56 will compress the expansion member, thereby expanding it against inside surface 24 of the top portion of golf club shaft 22. This expansion of expansion member 46 exerts a radially directed force on the shaft inside the sleeve, which in turn, exerts a radially directed force against the sleeve 28 and grip portion 32 of the assembly to hold the grip assembly in place on the shaft. Preferably, bolt 44 and nut 56 are configured and arranged so that the bolt cannot be removed from the nut, but it can be threaded into or partially unthreaded from the nut to apply or to remove a radially directed force on the inside surface 24 of the shaft.

In the embodiment of the invention shown in FIG. 1, grip portion 32 has an opening 58 at the top which communicates with the portion of cap 26 above intermediate portion 40 to allow a tool such as tool 60 (shown in FIGS. 11 and 13) or tool 188 (shown in FIGS. 12 and 13) to engage a tool engagement feature such as hex slot 62 in head 45 of bolt 44 (shown in FIGS. 10A and 10B). In addition, bolt 44 is provided with a central hole 64 which provides a pressure relief outlet from the interior of the shaft. In alternative embodiments of the invention, a fastener with a rounded head may be employed in connection with a grip portion that is open at the top.

FIGS. 14 and 15 illustrate alternative embodiments of the upper clamping mechanism of the invention. These embodiments include components that may be substituted for cap 26 (or cap 126), bolt 44 and expansion member 46 of the embodiment shown in FIG. 1. As shown in FIG. 14, a threaded fastener such as screw 144 is provided to mate with internally threaded expansion member 146. This expansion member is provided with a plurality of expansion slots, one of which, slot 145, is shown. In this embodiment of the invention, no nut (such as nut 56 that is associated with expansion member 46) is needed. Because the diameter of screw 144 is larger than that of the lower end of expansion member 146, threading of the screw into the expansion member will cause the expansion member to expand radially outwardly against the inside surface of the top portion of the golf club shaft, thereby exerting a radially directed force against the sleeve and grip to securely hold the grip assembly on the shaft. In this embodiment of the invention, the grip portion (not shown) will have an opening (such as opening 58 at the top of grip 32) which communicates with the inside of the sleeve to allow a tool (such as tool 60 or tool 188) to engage a tool engagement feature such as hex slot 162 in screw 144. In addition, screw 144 is provided with a central hole 164 which provides a pressure relief outlet from the interior of the golf club shaft. FIG. 15 illustrates an embodiment of the invention in which internally threaded expansion member 246 is essentially identical to expansion member 146 of FIG. 14, except that expansion member 246 is integrally formed with sleeve 228 and provided with an annular slot into which golf club shaft 22 may be placed. Expansion member 246 is provided with a plurality of expansion slots, one of which, slot 245, is shown. In this embodiment of the invention (as in the embodiment of FIG. 14), no nut (such as nut 56) is needed, and a screw, such as screw 144, may be threaded into the expansion member to cause the expansion member to expand radially outwardly against the inside surface of the top portion of the golf club shaft, thereby exerting a radially directed force against the integral sleeve and grip portion to securely hold the grip assembly on the shaft.

FIG. 16 illustrates an alternative embodiment of the threaded fastener illustrated in FIGS. 10A and 10B, and FIG. 17 illustrates an alternative embodiment of the threaded fastener illustrated in FIG. 14. As shown in FIG. 16, fastener 47 includes recess 49 in the upper surface of its head, which recess is adapted to receive ball marker 51. Preferably, ball marker 51 is removably secured in the recess by magnetic attraction. Similarly, as shown in FIG. 17, fastener 147 includes recess 149 in the upper surface of its head, which recess is adapted to receive ball marker 151. Preferably, ball marker 151 is removably secured in the recess by magnetic attraction.

FIGS. 18A, 18B, 18C, 19 and 20 illustrate first and second alternative embodiments of an attachment mechanism for the upper part of the shaft which comprises a threaded nut and a detent mechanism. As shown in FIG. 18B, threaded nut 330 includes an upper ring portion 332 and generally cylindrical nut portion 334 which includes internally threaded central hole 336. Preferably, nut portion 334 is sized to fit within the upper part of golf club shaft 22 and to be glued, bonded, integrally formed with or otherwise fixed to the inner surface 24 of the upper part of the shaft. Upper ring portion 332 preferably has an outside diameter that is essentially the same as that of shaft 22 so that when threaded nut 330 is affixed to the upper portion of shaft 22, sleeve 28 may be slid axially along the shaft without interference from nut portion 334. FIG. 20 illustrates an alternative golf club shaft 122 that is provided with external (or male) threads 360 on its upper end. Threaded nut 362, shown in FIG. 19, is provided with internal (or female) threads 364 that are adapted to threadably engage threads 360 on the upper end of golf club shaft 122 so that nut 362 can be secured thereto. Nut 362 also includes internally threaded central hole 366. In other embodiments of the invention (not shown in the drawings), the threaded nut may be provided with external (or male) threads that mate with corresponding internal (or female) threads in the top portion of the shaft. In the embodiments described herein which include internal or external threads on the shaft, such threads may be formed by any known thread cutting or milling methods, or by other known thread forming methods.

As shown in FIGS. 18A and 18B, cap member 340 is integrally formed with, glued, welded or otherwise affixed to the inside surface 29 of sleeve 28. In other embodiments of the invention, the cap member can be sized and shaped to obtain a friction fit with the inner surface of the sleeve or with respect to a grip portion that is integrally combined with at least a portion of the sleeve. In other embodiments of the invention, the cap member can be provided with outer surface features that serve to keep the cap member from rotating with respect to a sleeve or with respect to a grip portion that is integrally combined with at least a portion of the sleeve. Preferably, cap member 340 is recessed somewhat from the top of sleeve 28 and is affixed to the inner surface thereof, as shown in FIG. 18B. Cap member 340 includes central hole 342 and a plurality of detent features 344 that are adapted to mate with detent features 346 on the top of threaded nut 330, or with detent features 368 on the top of threaded nut 362. The detent features on the cap member and the threaded nut are complementary so that the mating of the cap member and the threaded nut will resist rotation of the cap member with respect to the threaded nut. Preferably, detent features 344 of cap member 340 comprise a series of adjacent angled detent surfaces 348 that are arranged to intersect at peak lines 350 and valley lines 352. In this embodiment of the invention, peak lines 350 and valley lines 352 are perpendicular to longitudinal axis 29 of sleeve 28. It is also preferred that the angle θ measured between each pair of adjacent detent surfaces 348 that intersect at a peak line 350 is within the range of about 45° to about 150°, most preferably about 90°. It is also preferred that the angle φ measured between each pair of adjacent detent surfaces 348 that intersect at a valley line 352 is equal to 180°−θ. Similarly, detent features 346 of threaded nut 330 comprise a series of adjacent angled detent surfaces 354 that are arranged to intersect at peak lines 356 and valley lines 358. In this embodiment of the invention, peak lines 356 and valley lines 358 are perpendicular to longitudinal axis 29 of sleeve 28. It is also preferred that the angle φ measured between each pair of adjacent detent surfaces 354 that intersect at a valley line 358 is within the range of about 45° to about 150°, most preferably about 120°, and that the angle φ measured between each pair of adjacent detent surfaces 354 that intersect at a peak line 356 is equal to 180°−θ.

FIG. 18C is a schematic view of the impending mating of detent features 344 of cap member 340 and detent features 346 of threaded nut 330. When a threaded fastener such as bolt 44 is passed through hole 342 of cap member 340 and advanced into threaded hole 336 of nut 330, detent surfaces 348 on cap member 340 will substantially contact and mate with detent surfaces 354 on threaded nut 330 to prevent sleeve 28 from rotating with respect to shaft 22. When cap member 340 is employed with the attachment mechanism for the upper part of shaft 122 that is illustrated in FIGS. 19 and 20, and a threaded fastener such as bolt 44 is passed through hole 342 of cap member 340 and advanced into threaded hole 366, detent features 344 on the cap will mate with corresponding detent features 368 on the nut to prevent sleeve 28 from rotating with respect to shaft 122.

An alternative to cap member 340 is cap member 370 (shown in FIGS. 21A and 21B). This cap member includes central hole 372 and a plurality of detent features 374 that are adapted to mate with corresponding detent features on the top of a threaded nut. These detent features comprise a series of adjacent angled detent surfaces that are similar to those of cap member 340, although in this embodiment of the invention, the adjacent angled detent surfaces intersect at peak lines and valley lines that are perpendicular to longitudinal axis 329 of sleeve 328 (shown in FIG. 22) but are closer together than those of cap member 340. Cap member 370 is also provided with radial projections 376, 378, 380 and 382 that are adapted to slide into and mate with slots on sleeve 328 (shown in FIG. 22). Thus, radial projection 376 of cap member 370 fits into slot 384 of sleeve 328, radial projection 378 fits into slot 386, radial projection 380 fits into a slot on the opposite side of sleeve 328 from slot 384, and radial projection 382 fits into slot 388. This mating of cap member 370 and sleeve 328, which may be enhanced with an adhesive or other bonding means) will keep the cap member from rotating with respect to the sleeve or with respect to a grip portion that is integrally attached to or combined with a sleeve. When sleeve 328 is placed over a shaft with a threaded nut that is provided with detent features which are adapted to mate with detent features 374 on the bottom of cap member 370, and a threaded fastener such as bolt 44 is passed through hole 372 of cap member 370 and advanced into the threaded hole of the nut, detent features 374 on cap member 370 will mate with the corresponding detent features on the threaded nut to prevent sleeve 328 from rotating with respect to the shaft.

FIGS. 23A, 23B and 24 illustrate another embodiment of an attachment mechanism for the upper part of the shaft which comprises a threaded nut and a detent mechanism. As shown therein, threaded nut 446 includes an upper ring portion 448 and generally cylindrical nut portion 449 which includes internally threaded central hole 450. Preferably, nut portion 449 is sized to fit within the upper part of golf club shaft 22 and to be glued, bonded, integrally formed with or otherwise fixed to the inner surface 24 of the upper part of the shaft. Upper ring portion 448 preferably has an outside diameter that is essentially the same as that of shaft 22 so that when threaded nut 446 is affixed to the upper portion of shaft 22, a sleeve (not shown, but essentially the same as sleeve 28 in FIG. 18B) may be slid axially along the shaft. Cap member 452 is integrally formed with, glued, bonded or otherwise affixed to the inside surface of the sleeve. Preferably, cap member 452 is recessed somewhat from the top of the sleeve, similar to the way that cap member 340 is recessed from the top of sleeve 28 as shown in FIG. 18B. Cap member 452 includes central hole 454 and a plurality of detent features comprising radially extending projections 456. Each pair of adjacent projections 456 is separated by a space 457. Projections 456 are adapted to mate with corresponding detent features on the top of threaded nut 446. The detent features on nut 446 comprise radially extending projections 458 that are separated by spaces 459. When a threaded fastener such as bolt 44 is passed through hole 454 of cap member 452 and advanced into threaded hole 450, projections 456 will mate with spaces 459 between projections 458, and correspondingly, projections 458 will mate with spaces 457 between projections 456 to prevent the sleeve from rotating with respect to shaft 22. Cap member 452 may also be provided with clocking markings 460 that may be aligned with similar markings (not shown) on the grip portion attached to the sleeve so that the proper mating of detent features on the cap member and the threaded nut can be easily obtained.

FIG. 25 illustrates an embodiment of the invention in which an attachment mechanism for the upper part of the shaft is mounted in an extension member that allows for effective extension of the shaft length. As shown therein, threaded nut 546 (which is essentially identical to nut 446 of FIG. 24) includes an upper ring portion 547 and generally cylindrical nut portion 548 which includes internally threaded central hole 549. Threaded nut 546 is glued, bonded, integrally formed with or otherwise affixed to an extension member which includes upper portion 550 and lower portion 551. In other embodiments of the invention, attachment mechanisms for the upper part of the shaft with different detent features from those of threaded nut 546 may be installed in an extension member. In still other embodiments, extension members may be provided with upper portions and/or lower portions of various lengths so that the effective length of shaft 22 may be varied to suit the preferences of multiple golfers.

It is also preferred that upper portion 550 of the extension member has an outside diameter that is essentially the same as the outside diameter of shaft 22, and that lower portion 551 of the extension member is sized to fit within the upper portion of the shaft. Preferably, nut portion 548 is sized to fit within upper portion 550 of the extension member, and is glued, bonded, integrally formed with or otherwise fixed to the inner surface 552 of the upper portion 550 of the extension member, and lower portion 551 of the extension member is glued, welded or otherwise fixed to the inner surface 24 of shaft 22. Upper ring portion 547 preferably has an outside diameter that is essentially the same as that of the extension member, so that so that when threaded nut 546 is affixed to the upper portion 550 of the extension member and lower portion 551 of the extension member is affixed to the upper part of shaft 22, a sleeve (not shown, but essentially the same as sleeve 28 in FIG. 18B) may be slid axially along the shaft. Cap member 452 (shown in FIGS. 23A and 23B) may be integrally formed with, glued, welded or otherwise affixed to the inside surface of the sleeve, and recessed somewhat from the top of the sleeve, similar to the way that cap member 340 is recessed from the top of sleeve 28 as shown in FIG. 18B. When a threaded fastener such as bolt 44 is passed through hole 454 of cap member 452 and advanced into threaded hole 549 of threaded nut 546, projections 456 will mate with spaces 559 between projections 558 of nut 546, and correspondingly, projections 558 will mate with spaces 457 between projections 456 to prevent the sleeve from rotating with respect to shaft 22.

FIG. 26 illustrates another embodiment of an attachment mechanism for the upper part of the shaft which comprises a threaded nut and a detent mechanism. As shown therein, threaded nut 646 includes an upper portion 650 that has an outside diameter which is essentially the same as that of shaft 122, so that when threaded nut 646 is affixed to the upper portion of shaft 122, a sleeve (not shown, but essentially the same as sleeve 28 in FIG. 18B) may be slid axially along the shaft. Threaded nut 646 also includes a lower portion 651 that is similar to lower portion 551 of threaded nut 546 and a plurality of projections 645 (one of which is shown) on the outer surface of lower portion 651. These projections are adapted to mate with corresponding slots 123 on shaft 122 for attachment of nut 646 to the shaft. This method of attachment can be enhanced by use of an adhesive or other bonding means between lower portion 651 of threaded nut 646 and shaft 122. In other embodiments of the invention, the shaft may be provided with female (or internal) threads and the exterior surface of the threaded nut with male (or external) threads adapted to mate therewith. In such an embodiment, the threaded nut may simply be threaded into engagement with the shaft.

Threaded nut 646 also includes internally threaded central hole 650. Cap member 652 is integrally formed with, glued, bonded, integrally formed or otherwise affixed to the inside surface of the sleeve. Preferably, cap member 652 is recessed somewhat from the top of the sleeve, similar to the way that cap member 340 is recessed from the top of sleeve 28 as shown in FIG. 18B. Cap member 652 includes central hole 654 and a detent feature 655 that is adapted to mate with any of the detent features on the top of threaded nut 646. Preferably, the detent feature 655 of cap member 652 comprises a pair of adjacent angled detent surfaces that are arranged to intersect at peak line 660 and abut inner cylindrical surface 661 at a pair of valley lines 662. The detent features of threaded nut 646 comprise a series of adjacent angled detent surfaces 664 that are arranged to intersect at peak lines 666 and valley lines 668. These peak lines and valley lines are parallel to the longitudinal axis of the sleeve. Preferably, the angle θ measured between each pair of adjacent detent surfaces 664 that intersect at a valley line 668 is within the range of about 45° to about 150°, most preferably about 120°, and that the angle φ measured between each pair of adjacent detent surfaces 664 that intersect at a peak line 666 is equal to 180°−θ. Similarly, the adjacent detent surfaces of detent feature 655 of cap member 652 are parallel to those of detent surfaces 664 of nut 646 so that these detent features will mate in a manner similar to that shown in FIG. 18C, when a threaded fastener such as bolt 44 is passed through hole 654 of cap member 652 and advanced into threaded hole 650, to prevent the sleeve (not shown) from rotating with respect to shaft 122. In other embodiments of the invention, the cap member may be provided with two or more detent features, but fewer than those on the threaded nut, so long as the detent features on the cap member are spaced and configured to mate with the detent features on the threaded nut.

FIGS. 27 and 28 illustrate another embodiment of an attachment mechanism for the upper part of the shaft which comprises a threaded nut and a detent mechanism. As shown therein, threaded nut 746 is generally hexagonal and includes internally threaded central hole 750. Preferably, nut 746 is sized to fit within the upper part of golf club shaft 22 and to be glued, welded or otherwise fixed to the inner surface of the upper part of the shaft. Cap member 752 is sized slightly larger than nut 746 and is adapted to be glued, welded or otherwise affixed to the inside surface of the sleeve (not shown in FIGS. 27 and 28, but essentially identical to sleeve 28 shown in FIG. 18B). Preferably, cap member 752 is recessed somewhat from the top of the sleeve, similar to the way that cap member 340 is recessed from the top of sleeve 28 as shown in FIG. 18B. Cap member 752 includes central hole 754 and at least two detent pins 756 that are adapted to mate with detent recesses 758 on the top of threaded nut 746. When detent pins 756 in cap member 752 are aligned with corresponding detent recesses 758 in threaded nut 746 and a threaded fastener such as bolt 44 is passed through hole 754 of cap member 752 and advanced into threaded hole 750, engagement of the detent features will prevent the sleeve from rotating with respect to shaft 22.

FIG. 29 illustrates another preferred embodiment of an attachment mechanism for the upper part of the shaft which comprises a threaded nut and a detent mechanism. As shown therein, threaded nut 846 includes a lower portion 848 that is sized to fit within the upper part of golf club shaft 22 and an upper portion 850 that has an outside diameter that is essentially the same as the outside diameter of shaft 22. Lower portion 848 may be sized to create a friction fit or interference fit with shaft 22 and/or upper portion 850 may be affixed to or integrally formed with the upper surface of the shaft. Threaded nut 846 also includes internally threaded central hole 852. Grip portion 832 in this embodiment of the invention is rigid enough to include an integral sleeve and to support integral portion 834 of a detent mechanism that is adapted to cooperate with a corresponding portion of a detent mechanism in upper portion 850 of threaded nut 846. Preferably, the portion of the detent mechanism of integral portion 834 of grip portion 832 comprises a series of adjacent angled detent surfaces that are arranged to intersect at peak lines and valley lines (similar to other embodiments of the attachment mechanism described herein). In this embodiment of the invention, the peak lines and valley lines are perpendicular to the longitudinal axis of grip portion 832 with its integral sleeve (similar to the peak lines and valley lines in the attachment mechanism of FIGS. 18B and 19). Similarly, the portion of the detent mechanism of threaded nut 846 comprises a series of adjacent angled detent surfaces that are arranged to intersect at peak lines and valley lines which are also perpendicular to the longitudinal axis of grip portion 832. When a threaded fastener such as bolt 44 is passed through a hole in overcap 854 and through a hole in the top of grip portion 832 and advanced into threaded hole 852, the detent surfaces on integral portion 834 of grip portion 832 will substantially contact and mate with detent surfaces on upper portion 850 of threaded nut 846 to prevent the grip portion with integral sleeve from rotating with respect to shaft 22.

FIG. 30 illustrates an alternative embodiment of the invention that includes an attachment mechanism for the upper part of the shaft which comprises a threaded nut and a detent mechanism. As shown therein, grip assembly 900 comprises sleeve 902 that is adapted to fit over hollow golf club shaft 22. Threaded nut 904 includes a lower portion 906 that is sized to fit within the upper part of golf club shaft 22, top portion 908 that is provided with detent surfaces similar to those of threaded nut 846 and an intermediate ledge portion 910 that has an outside diameter that is essentially the same as the outside diameter of shaft 22. Lower portion 906 may be sized to create a friction fit or interference fit with shaft 22 and/or intermediate ledge portion 910 may be bonded to or otherwise affixed to the upper surface of the shaft. Threaded nut 904 also includes internally threaded central hole 912. Grip assembly 900 also includes cap 914 that is provided with detent surfaces that are adapted to engage with the detent surfaces on top portion 908 of threaded nut 904 in order to form a detent mechanism. Cap 914 also includes through hole 915 that may be threaded. Relatively rigid reinforcing cap 916 (also shown in FIGS. 31A, 31B and 31C) is placed over cap 914 to provide additional strength to the detent mechanism formed between cap 914 and nut 904. As shown in FIGS. 31A, 31B and 31C, reinforcing cap 916 includes hole 918 in its top wall, and the grip assembly includes overcap 922 that may be provided in any of various weights. The overcap also is provided with a hole so that a threaded fastener such as bolt 44 may be placed through the hole in the overcap, and through hole 918 in the top wall of reinforcing cap 916, and through hole 915 in cap 916 to be threaded into hole 912 of nut 904. This will cause the portion of the detent mechanism on the cap member to substantially contact and mate with the portion of the detent mechanism on the threaded nut to prevent sleeve 902 from rotating with respect to shaft 22. Grip assembly 900 also includes generally hollow grip portion 920 that is adapted to fit over the sleeve. Grip portion 920 can be provided in any suitable configuration and in any convenient length. Preferably, sleeve 902 is provided with an annular rib 923 at its bottom end that can be engaged by clamp 924.

FIGS. 32A and 32B illustrate a first embodiment 925 of an alternative overcap. This overcap is provided with central hole 926 (similar to the central hole in overcap 922) that is adapted to receive a threaded fastener such as bolt 44, and a cavity 927 that is adapted to receive a washer of any of various weights to modify balance of the golf club. FIGS. 32C and 32D illustrate a second embodiment 930 of an alternative overcap. Overcap 930 is comprised of first portion 932 having a first density D₁ and second portion 934 having a second density D₂ that is different from the first density D₁ in order to modify the balance of the golf club. Although portions 932 and 934 of overcap 930 are shown as having essentially the same volume (or occupying equal 180° radial portions of the overcap), one may be larger than the other, or there may be three or more portions, each of which has a density that is different from the others. Overcap 930 includes central hole 936 (similar to the central hole in overcap 922) that is adapted to receive a threaded fastener.

FIG. 33 illustrates an embodiment of a sleeve 1050 that includes slits 1052, 1054 and 1056 at its lower end that are of different lengths and is provided with rifling grooves or projections 1057 that enable the sleeve to be “twisted” onto the golf club shaft.

Alternative sleeves 1058, 1060, 1062, 1064, 1066, 1068, 1070 and 1072 are illustrated in FIG. 34, each of which is provided with a slit that extends only along a portion of the length of the sleeve. As shown therein, these alternative slits may be provided with various configurations at the bottom of the sleeve, each of which includes a cut-out of a different configuration. These embodiments of the sleeve will accommodate multiple shaft diameters and shafts having varying diameters.

FIGS. 35A and 35B illustrate a first embodiment of a grip portion that is comprised of two materials of different densities, each of which comprises a different part of the grip portion. As shown therein, grip portion 1074 comprises a first material of a first density D₁ that occupies radial portion 1076 comprising 180° of the circumference of the grip portion and a second material of a second density D₂ that is different from the first density D₁ that occupies radial portion 1078 also comprising 180° of the circumference of the grip portion. In other embodiments of the invention, the materials of different densities may occupy differently sized radial portions of the grip assembly. Preferably, however, a first material having a density of D₁ occupies a radial portion R₁ comprising at least about 90° of the circumference of the grip portion, and a second material having a density D₂ that is different from density D₁ occupies a radial portion R₂ comprising 360°-R₁ of the circumference of the grip portion. In other embodiments of the invention, three or more materials, each having a different density, may occupy differently sized radial portions of the grip assembly.

FIGS. 36A and 36B illustrate a second embodiment of a grip portion that is comprised of two materials of different densities. As shown therein, grip portion 1080 comprises a first material of a first density D₁ that occupies a portion 1082 of the grip portion that extends for a length L₁ in a direction that is parallel to the axis of the grip portion, and a second material of a second density D₂ that is different from the first density D₁ that occupies the remainder 1084 of the space occupied by the grip portion. In this embodiment of the invention, the outer surface of portion 1082 occupies about 50° of the circumference of grip portion 1080, and the distance L₁ comprises about 18% of the total length of grip portion 1080. In other embodiments of the invention, the materials of different densities may occupy differently sized radial portions and/or portions of different lengths of the grip assembly. In other embodiments of the invention, three or more materials, each having a different density, may occupy differently sized radial portions and/or portions of different lengths of the grip assembly. These materials of different densities may be made or assembled by various methods known to those having ordinary skill in the art to which the invention relates. The embodiments of the invention illustrated in FIGS. 36A and 36B, along with other embodiments described herein that are adapted to modify the weight distribution of the grip assembly, provide a golf club grip that can be removably located at different rotational positions on the shaft in order to modify the balance of the golf club.

The invention provides an easily interchangeable golf club grip assembly that includes both upper and lower mechanisms for securing the grip to the shaft of the golf club by applying attachment forces to the shaft at two separate locations. The assembly can be easily removed in order to replace the grip or to change the axial or rotational location of the grip assembly on the shaft. The invention can also incorporate a grip portion that is provided with anti-slip surface characteristics.

FIG. 37 illustrates a layer of mesh fabric 2010 that may be employed in the invention. Preferably, the fabric is an open mesh having a surface that is coated with silicon carbide or aluminum oxide particles having a grit size within the Federation of European Producers of Abrasives (“FEPA”) standard range of P12 (average grain diameter 1815 μm) to P1200 (average grain diameter 15.3 μm). Such products are commonly sold as “drywall sandpaper” or “sanding screen”. The diameter and spacing of the threads in mesh fabric 2010 may be of any convenient dimensions. Preferably, the diameter of such threads is within the range of 0.02-0.125 inches, and the spacing between threads is within the range of 0.01-0.4 inches. Preferably, the threads intersect at right angles, as shown in FIG. 37, although they may also intersect at any convenient angle within the range of 30°-90°.

FIG. 38 illustrates injection mold assembly 2012 comprising upper section 2014 and lower section 2016. Mold assembly 2012 includes a generally cylindrical cavity 2018 in the center of which is located mandrel 2020 that has an outer diameter comparable to that of a golf club shaft. Sleeve 2022 of plastic or other suitable material is placed on the mandrel, and around the sleeve is placed a mesh fabric 2010 that has been folded so as to comprise two layers that extend generally around the sleeve. Because the preferred fabric is somewhat stiff, the outer of the two layers will tend to abut the inner surface of cavity 2018 of the mold assembly, as shown in FIG. 38.

Upper section 2014 of mold assembly 2012 has a pair of risers 2024 and 2026 that communicate with cavity 2018 by way of cross-passages 2028 and 2030. When the sleeve and fabric are placed over the mandrel in the mold assembly, as shown in FIG. 38, uncured elastomer is injected through risers 2024 and 2026 and flows through the cross-passages and into cavity 2018. The elastomer will generally encapsulate the fabric, although at least a portion of the outer surface thereof will be exposed adjacent the inner surface of cavity 2018. When the elastomer is cured with heat, the finished grip is removed from the mold assembly.

FIG. 39 illustrates an alternative embodiment of the components of a grip sub-assembly that is adapted to be placed over a mandrel such as mandrel 2020. As shown therein, a pair of spacers 2032 are placed over sleeve 2022 and a single-layer of fabric that has been formed into a cylinder 2034 is placed over the spacers. Any number of spacers may be used, and they may have any convenient dimensions, so long as they are adapted to fit over sleeve 2022 and within fabric cylinder 2034. This sub-assembly may then be placed into cavity 2018 of mold assembly 2012 and uncured elastomer injected into risers 2024 and 2026. The injected elastomer will flow through cross-passages 2028 and 2030 into cavity 2018. The elastomer will generally encapsulate the fabric, although at least a portion of the outer surface thereof will be exposed adjacent the inner surface of cavity 2018. When the elastomer is cured with heat, the finished grip is removed from the mold assembly.

In an alternative to the arrangement of FIG. 39 (not shown), the sub-assembly that is placed over mandrel 2020 may comprise one or more layers formed of strips of fabric that are spirally wound around the sleeve or around a plurality of spacers that have been placed over the sleeve. In another embodiment of the invention, fabric 2036 is formed into a double-walled cylindrical configuration for placement directly onto mandrel 2038, as shown in FIG. 40.

FIG. 41 illustrates various fabric surface textures that may be employed in connection with the invention. Although all of the fabrics shown therein extend generally the entire length of the grip, they may be of any convenient length and may be interrupted along the length of the grip.

Although FIGS. 1, 2, and 29 illustrate grip assemblies having a circular cross-section and a grip axis (i.e., the axis through the center of the grip portion) that is coincident with the central axis of the shaft, it is within the scope of the invention to include grip assemblies that are installed on the shaft in such a way that the grip axis is not coincident with the central axis of the shaft, in order to modify the loft and/or lie angles of the golf club. For example, the standard putter has a built-in 4° loft angle and a built-in 15° lie angle. By providing the grip portion of the grip assembly with a bore that is angled with respect to the shaft axis, the grip assembly can be placed on the shaft at an angle that will modify either or both of the built-in loft angle and the built-in lie angle of the club. Depending on the diameter of the grip portion and the angle of its bore with respect to the grip axis, the built-in loft and lie angles can be varied by up to about 8°, although a variation of 2°-3° from the standard angles would be useful for most golfers.

The Rules of Golf allow for grips to be installed on a golf club shaft in such a way that the grip axis is offset from the shaft axis. FIG. 42 illustrates a grip assembly 920 having a grip portion 940 with a bore axis that is not coincident with the central axis of the sleeve. Thus, as shown therein, shaft 22 includes threaded nut (not shown), which is covered by reinforcing cap 946 (also shown in FIGS. 43A and 43B) that is shaped and sized to create a friction fit or interference fit with the top portion of the shaft. The threaded nut includes a portion of a detent mechanism such as is described in other embodiments of the invention. Cap member 970 includes a corresponding or mating portion of a detent mechanism and is attached to the inner surface of sleeve 928. The sleeve is placed over shaft 22 until the portion of the detent mechanism of cap member 970 mates with the portion of the detent mechanism on the threaded nut. Cap member 970 also includes a central hole (not shown) that is aligned with a threaded hole in the threaded nut, so that a threaded fastener such as bolt 44 may be passed through hole 950 in overcap 954, through a hole in cap member 970 and through a hole in reinforcing cap 946, and advanced into the threaded hole in the threaded nut. This will cause the portion of the detent mechanism on the cap member to substantially contact and mate with the portion of the detent mechanism on the threaded nut to prevent sleeve 928 from rotating with respect to shaft 22.

FIG. 44 illustrates another golf club grip assembly, namely grip assembly 100, that is attached to golf club shaft 102 in such a way that grip axis 104 is not coincident with central axis 106 of the shaft. Depending on the orientation of the grip on the shaft, an offset grip will modify either or both of the built-in loft angle and the built-in lie angle. Grips that may be installed in such a way that the grip axis is offset from the shaft axis must be at least ten inches long, and they cannot provide a loft angle of more than 10° or a lie angle of less than 10°. If it is assumed that: (a) grip length is 10″, and (b) the golf club shaft has a wall thickness of 0.6 inches, and (c) the shaft should not come any closer to either side of the grip than 0.125″, and (d) the shaft should not come any closer to the top of the grip than 0.5″, the maximum offset angle A° for a grip having a circular cross-section of diameter D can be determined as follows:

${A{^\circ}} = \frac{100\left( {D - 0.85} \right)}{10.55}$

Thus, the maximum offset angle A° for a grip having a circular cross-section of diameter 1.0″ is:

A°=100 (0.15)=1.42°/10.55.

The maximum offset angle A° for a grip having a circular cross-section of diameter 1.25″ is:

A°=100 (0.4)=3.79°/10.55.

The maximum offset angle A° for a grip having a circular cross-section of diameter 1.5″ is:

A°=100 (0.65)=6.16°/10.55.

The maximum offset angle A° for a grip having a circular cross-section of diameter 1.75″ is:

A°=100 (0.9)=8.53°/10.55.

This same formula can be used to determine the maximum offset angle for grips having a non-circular cross-section, if the longest dimension across the width of the grip is substituted for “D” in the formula.

FIG. 45 illustrates the grip assembly and shaft of FIG. 44 in eight different angular orientations showing the effect that these orientations have on the lie angle and/or the loft angle of the club head that is attached to the shaft. These orientations are viewed from the top of the grip assembly and include opening 158, which is similar to opening 58 in assembly 20. On the top row of FIG. 45, on the right side is illustrated a grip orientation that provides a positive offset A_(F) to the loft angle. This positive offset A_(F) to the loft angle is also illustrated in FIG. 46B. On the top row of FIG. 45, the illustration second to the right side illustration shows a grip orientation that provides a negative offset A_(F) to the loft angle. This negative offset A_(F) to the loft angle is also illustrated in FIG. 46A. On the top row of FIG. 45, on the left side is illustrated a grip orientation that provides a positive offset A_(E) to the lie angle. This positive offset A_(E) to the lie angle is also illustrated in FIG. 46C. On the top row of FIG. 45, the illustration second to the left side illustration shows a grip orientation that provides a negative offset A_(E) to the lie angle. This negative offset A_(E) to the lie angle is also illustrated in FIG. 46D. On the bottom row of FIG. 45, from left to right, are illustrated combination offsets to the loft and lie angles, respectively (a) a positive lie offset and a positive loft offset, (b) a positive lie offset and a negative loft offset, (c) a negative lie offset and a negative loft offset, and (d) a negative lie offset and a positive loft offset.

Although this description contains many specifics, these should not be construed as limiting the scope of the invention but as merely providing illustrations of the presently preferred embodiments thereof, as well as the best mode contemplated by the inventor of carrying out the invention. The invention, as described herein, is susceptible to various modifications and adaptations, as would be understood by those having ordinary skill in the art to which the invention relates. 

1. A grip assembly for a golf club that is adapted to be removably attached to the upper portion of a golf club shaft, said grip assembly comprising: (a) a sleeve that is adapted to fit over the upper portion of the shaft, said sleeve having: (i) a top end; (ii) a bottom end; (b) a grip portion that is adapted to provide a gripping surface for a golfer; (c) an upper mechanism for removably securing the top end of the sleeve to the golf club shaft; (d) a lower mechanism for removably securing the bottom end of the sleeve to the golf club shaft by applying a radially-directed compression force to the sleeve on the shaft.
 2. The grip assembly of claim 1 wherein the grip portion is integrally combined with at least a portion of the sleeve.
 3. The grip assembly of claim 1 wherein the upper mechanism for removably securing the top end of the sleeve to the golf club shaft applies a radially-directed compression force to the sleeve on the shaft.
 4. The grip assembly of claim 1 which includes an overcap that is adapted to modify the balance of the golf club to which the grip assembly is attached.
 5. The grip assembly of claim 4 which includes an overcap that is adapted to receive any of a plurality of differently weighted washers.
 6. The grip assembly of claim 1 wherein the lower mechanism for removably securing the bottom end of the sleeve to the golf club shaft comprises: (a) external threading on the bottom end of the sleeve; (ii) a nut that is adapted to fit over the golf club shaft and is provided with internal threading that is adapted to mate with the external threading on the bottom end of the sleeve.
 7. The grip assembly of claim 1 wherein the lower mechanism for removably securing the bottom end of the sleeve to the golf club shaft is selected from the group consisting of clamps, elastomeric bands and O-rings.
 8. The grip assembly of claim 1 wherein; (a) the sleeve has a central axis; (b) the grip portion has a grip axis that is not coincident with the central axis of the sleeve.
 9. The grip assembly of claim 8 wherein the grip axis is offset from the central axis by an angle within the range of 0.5° to 6.0°.
 10. The grip assembly of claim 8 wherein the grip assembly is adapted to be rotationally positioned on the shaft in various orientations, each of which is selected to modify the lie angle and/or the loft angle of the club head that is attached to the shaft.
 11. The grip assembly of claim 1 wherein the grip portion comprises a layer of mesh fabric having a surface that is coated with particles selected from the group consisting of silicon carbide and aluminum oxide particles.
 12. The grip assembly of claim 1 wherein the grip portion comprises a plurality of materials, each of which: (a) has a density that is different from that of the other materials; (b) comprises a different part of the grip portion.
 13. The grip assembly of claim 12 wherein the grip portion comprises: (a) a first material of a first density D₁ that occupies a radial portion R₁ comprising at least about 90° of the circumference of the grip portion; (b) a second material of a second density D₂, which second density D₂ is different from D₁, wherein the second material occupies a radial portion R₂ comprising 360°-R₁ of the circumference of the grip portion.
 14. The grip assembly of claim 1 wherein the sleeve has an outer surface that includes a surface feature which is adapted to assist in preventing the grip portion from moving with respect to the sleeve when the grip portion and sleeve are assembled together.
 15. The grip assembly of claim 1 wherein the sleeve has an outwardly extending lip at the bottom end.
 16. The grip assembly of claim 1 wherein the sleeve has a slit at the bottom end.
 17. The grip assembly of claim 16 wherein the slit comprises a tapered opening that is wider at the bottom of the slit than at the top of the slit.
 18. The grip assembly of claim 16 wherein the slit extends from the bottom end of the sleeve to the top end of the sleeve.
 19. The grip assembly of claim 1 wherein the upper mechanism for removably securing the top end of the sleeve to the golf club shaft comprises: (a) a threaded fastener; (b) a cap that is attached to the sleeve and has a hole through which the threaded fastener may pass; (c) an expansion member that: (i) is adapted to fit in the top end of the golf club shaft; (ii) has a central hole that is threaded to receive the threaded fastener; (iii) is adapted to expand radially outwardly when the threaded fastener is advanced into the central hole.
 20. The grip assembly of claim 19 wherein the expansion member is flexible and includes an integral nut.
 21. The grip assembly of claim 19 wherein the expansion member includes a plurality of expansion slots.
 22. The grip assembly of claim 19 wherein the threaded fastener is provided with a relief opening.
 23. The grip assembly of claim 19 wherein a plurality of interchangeable caps are provided, each of which has a different weight.
 24. The grip assembly of claim 1: (a) which is adapted to be removably attached to the upper portion of a golf club shaft having a detent feature; (b) wherein the upper mechanism for removably securing the top end of the sleeve to the golf club shaft includes a plurality of components, at least one of which includes a detent feature that cooperates with the detent feature on the golf club shaft to form a detent mechanism that is adapted to prevent movement of the sleeve with respect to the golf club shaft.
 25. The grip assembly of claim 24 wherein: (a) the detent feature in the upper portion of the golf club shaft comprises a slot; (b) the detent feature of a component of the upper mechanism for removably securing the top end of the sleeve to the golf club shaft comprises a radially extending projection that is adapted to be received in the slot in the upper portion of the golf club shaft in order to prevent the sleeve from rotating with respect to the shaft.
 26. The grip assembly of claim 1 wherein the upper mechanism for removably securing the top end of the sleeve to the golf club shaft comprises: (a) a threaded fastener; (b) a cap that is attached to the sleeve and has a hole through which the threaded fastener may pass; (c) an upper shaft component that: (i) is adapted to be secured within the top end of the golf club shaft; (ii) has a hole that is threaded to receive the threaded fastener; wherein the cap and the upper shaft component together comprise a detent mechanism that is adapted to prevent movement of the sleeve with respect to the golf club shaft when the threaded fastener is threaded into the hole in the upper shaft component.
 27. The grip assembly of claim 26 which includes a reinforcing cap to provide additional strength to the detent mechanism.
 28. The grip assembly of claim 26 wherein the grip portion is integrally combined with at least a portion of the sleeve and includes an integral cap comprising a portion of a detent mechanism that is adapted to engage a cooperative portion of a detent mechanism on the upper shaft component.
 29. The grip assembly of claim 26 wherein the detent mechanism comprises detent features on the cap and the upper shaft component that are configured for complementary mating so that such mating of the cap and the upper shaft component will prevent the sleeve from rotating with respect to the shaft.
 30. The grip assembly of claim 26 wherein: (a) the cap includes a detent feature comprising a radially extending projection; (b) the upper shaft component includes a detent feature comprising a slot; wherein the radially extending projection of the cap is adapted to be received in the slot of the upper shaft component to comprise a detent mechanism that is adapted to prevent movement of the sleeve with respect to the golf club shaft when the threaded fastener is threaded into the hole in the upper shaft component.
 31. The grip assembly of claim 30 which includes clocking markings associated with the detent features that may be aligned to facilitate removably securing the top end of the sleeve to the golf club shaft.
 32. The grip assembly of claim 26 wherein the detent features on each of the cap and the upper shaft component comprise a series of adjacent angled detent surfaces that are arranged to intersect at peak lines and valley lines.
 33. The grip assembly of claim 32 wherein: (a) the sleeve has a longitudinal axis; (b) the peak lines and valley lines are perpendicular to the longitudinal axis of the sleeve.
 34. The grip assembly of claim 32 wherein: (a) each pair of adjacent detent surfaces on the cap that intersect at a peak line form an angle θ; (b) each pair of adjacent detent surfaces on the cap that intersect at a valley line form the angle φ that is equal to 180°−θ; (c) each pair of adjacent detent surfaces on the upper shaft component that intersect at a valley line form an angle θ; (d) each pair of adjacent detent surfaces on the upper shaft component that intersect at a peak line form the angle φ that is equal to 180°−θ;
 35. The grip assembly of claim 32 wherein: (a) the angle θ between each pair of adjacent detent surfaces on the cap that intersect at a peak line is within the range of about 45° to about 150°; (b) the angle θ between each pair of adjacent detent surfaces on the upper shaft component that intersect at a valley line is within the range of about 45° to about 150°. 